The present invention relates to improvements in gas turbine engines and nacelles therefor and, more particularly, to a novel gas turbofan engine which exhibits lower noise levels, improved fuel comsumption, greater reliability, easier maintainability, easier replaceability, and improved thrust reversal over prior art gas turbofan engines.
Considerable attention has been devoted to developing a gas turbine engine which is quiet, clean and economical to operate. Significant improvement has been made in fuel consumption and noise levels of gas turbine engines over the past decade. Accordingly, a new family of high bypass, large diameter turbofans has recently been introduced into service. These engines have demonstrated noise levels and fuel consumption characteristics far superior to prior art gas turbine engines.
One of the operational requirements of such aircraft gas turbine engines is that of quick reversal from forward to reverse thrust for breaking purposes after landing. Accordingly, such engines have included various schemes for reversing the forward thrust delivered by the engine. In conventional high bypass engines, this has generally been accomplished by the use of blocker doors and other apparatus for reversing the exhaust direction of the bypass stream. In addition to reversing the bypass stream exhaust direction, such engines have also had to employ mechanisms for reducing the forward thrust of the core engine. Accordingly, they have included core engine exhaust flow thrust spoilers or thrust reversers in addition to the bypass stream reversers.
It is, therefore, a primary object of the present invention to provide an economical , easily maintained gas turbofan engine with improved thrust reversal.